Author Archives: Robin Dong

A example of Mesos Python Framework to calculate Pi

I have written an example of Mesos Framework by python. It simply calculate “Pi” by using Mento-Carlo algorithm The whole source code is at At beginning, I use python threading in “launchTask()”:

But I found out that the executors only spend a small part of CPU resource in… Read more »

Override the __init__ of BaseHTTPRequestHandler in python

Currently, I am writing some python program for the front of our storage system. By using ‘BaseHTTPRequestHandler’ and ‘ThreadedHTTPServer’, we could implement a simple multi-thread http server quickly. But after add ‘__init__()’ for our ‘MyHandler’, it doesn’t work correctly now:

Then I found this statement in python docs:

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puppet 3 certification problem on centos 7

I configure the puppet master and agent followed by this step. But when I run “puppet agent -t”, it report error:

My OS version is “Centos 7” and puppet version is “3.7.5”. After I have tried the way as this page answered, the problem still exists. Therefore, I write… Read more »

How to set the value of “$releasever” permanently for yum

In a test server I typed “sudo yum update”, it reported errors like:

Then I found this web in google for introducing how to get the value of “$releasever”, but it does not tell us how to set “$releasever” permanently. Therefore, I have to search word like “releasever” in… Read more »

Vault Conference 2015, in Boston

Vault Conference 2015 Registration First talk, and the sponsors John Spray and his talk about development updates of Ceph I and Coly also give a presentation about our Cold Storage project, the slide is here: Lambert: Achieve High Durability, Low Cost & Flexibility at Same Time — open source cold… Read more »

128bit atomic operation in arm64

In x86_64 architecture, we could use cmpxchg16b to compare and exchange a 128bit value in one atomic operation. But how to operate a 128bit value in aarch64 architecture (arm64) machine ? The answer is __atomic_compare_exchange(). As below code:

use “gcc test.c -o test” to compile code, but it reports:… Read more »